Non-volatile resistive memory devices are an important element of integrated circuit devices due to their ability to store data absent a power supply. Resistive memory cells, such as resistive random access memory (RRAM) cells, store data by switching between resistance states. For example, for binary data storage, a high-resistance state of the resistive memory cell may be read as logical “1,” while a low-resistance state of the resistive memory cell may be read as logical “0.” Switching between resistance states may be achieved by applying different physical signals (e.g., voltage, current, etc.) across the resistive memory cell to form, at least partially remove, or repair conductive filaments in a resistive memory element therein. Forming the conductive filaments can decrease the resistance of the memory cell, removing the conductive filaments can increase the resistance of the memory cell, and repairing the conductive filaments can decrease the resistance of the memory cell once again. Conventionally, the initial formation of the conductive filaments is referred to as “forming,” the at least partial removal of the conductive filaments is referred to as “resetting,” and the repair of the conductive filaments is referred to as “setting.”
Oxide-based resistive memory cells, in particular, are attractive because of their simple structure and method of operation. In conventional oxide-based resistive memory cells, the resistive memory element includes a switchable resistance material, such as a dielectric metal oxide, between a first electrode and a second electrode. Conductive filaments in formed by removing oxygen atoms from the switchable resistance material to form oxygen vacancies therein. The conductive filaments can be reset by inserting oxygen atoms back into the switchable resistance material to fill the oxygen vacancies. The conductive filaments can be set by again removing oxygen atoms from the switchable resistance material to reform the oxygen vacancies. However, problems such as instability of operational parameters, poor yield, poor on/off resistance ratio, and unsatisfactory switching endurance resulting from deficiencies in conventional methods of forming resistive memory elements have limited the commercial potential of resistive memory cells and resistive memory cell devices.
It would, therefore, be desirable to have an improved method of forming resistive memory elements for resistive memory cells to overcome one or more of the above problems.